Heat index rises above 100 amid poor air quality

Scott Dance, The Baltimore Sun

4:41 p.m. update: The Maryland Department of the Environment has extended its "Code Orange" air quality alert through Thursday evening. Children, the elderly, people with asthma and other sensitive groups are urged to avoid strenuous activity or exercise outdoors.

3:17 p.m. update: Today has set another new mark for hottest day of 2013 in Baltimore, with BWI at 96 degrees as of 3 p.m. With humidity, it feels like 100 degrees there. At the Inner Harbor, it feels like 103 degrees with an air temperature of 98 degrees.

1:17 p.m. update: Heat index values climbed above 100 degrees in the Baltimore area by midday. As of 1 p.m., the Inner Harbor reached 96 degrees with humidity making it feel like 102 degrees. At Baltimore-Washington International Airport, it felt like 97 degrees with air temperatures at 93 degrees.

Original post, 6:00 a.m.: A continuing heat wave is forecast to bring highs in the mid- to upper-90s across the region Wednesday, with an air quality alert in place through the evening.

Highs are expected in the upper 90s in the city and mid-90s in the suburbs, with heat index values near or above 100 degrees.

A slight chance of thunderstorms is possible in the evening. Otherwise, clear to partly cloudy skies are forecast.

The Maryland Department of the Environment has placed the region under a “Code Orange” air quality alert across Central Maryland today. Code Orange indicates air pollution levels unhealthy for sensitive populations, including children, the elderly and those with certain health conditions such as asthma.

A combination of high temperatures, sunshine and light winds will help ozone build up in the atmosphere, and it could be worse on Thursday, according to MDE.

More of the same heat and humidity are forecast Thursday and Friday, with a slight break coming Saturday and Sunday.